LOCALIZATION OF 5S rDNA IN THE PIG, THE BABIRUSA AND THE WHITE-LIPPED PECCARY BY FLUORESCENCE IN SITU HYBRIDIZATION (LOCALIZACIÓN DEL 5S rDNA EN EL CERDO, EL BABIRUSA Y EL PÉCARI DE HOCICO BLANCO MEDIANTE HIBRIDACION FLUORESCENTE IN SITU)

Mellink C.H.M.

Description

Abstract
In higher eukaryotes, the genes for ribosomal RNA (rDNA) are organized in two distinct gene classes that are represented by highly repeated gene families. One rDNA class comprises the genes encoding 185, 5.85, and 28S ribosomal RNA, the other class comprises the genes coding for 5S ribosomal RNA. To the present study. we localized 5S rDNA in the domestic pig (Sus scrofa, 2n=38) and in its wild relatives the babirusa (Babyrousa babyrussa, 2n=38) and the white-sipped peccary (Tayassu pecan, 2n=26). The pig and the babirusa both belong to the Suidae while the peccary is placed in a separate family, Dicotylidae.
Metaphase chromosomes were prepared from blood lymphocytes following standard procedures, and chromosomes were GTG-banded prior to hybridization. Fluorescence in situ hybridization was carried out using a mouse probe that included the 121 up 5S rRNA gene. The numbering of the chromosomes of the babirusa and the peccary is according to Bosma and de Haan (1981) and Huffy et al. (1973), respectively.
The 5S rRNA genes (RN5S) were mapped to pig chromosome 14q Z2, to babirusa chromosome 16, and to peccary chromosome 11. Based on the G-banding pattern, pig chromosome 14 corresponds to babirusa chromosome 16. Our data show that the regional position of the RN5S locus on this specific chromosome is in both species identical. In the peccary, the 5S rRNA genes were mapped to the distal region of the long arm of chromosome 11. To our knowledge, RN 5S is the first gene locus assigned in this species by in situ hybridization. Moreover, this result indicates that at least a part of chromosome 11 of the white-tipped peccary is homologous to a part of pig chromosome 14. Since the G banding patterns of these chromosomes do not show any apparent similarities, further mapping or chromosome painting is needed to clarifythe extent of the conserved region.
Resumen
En los eucariotas superiores, los genes para el RNA ribosómico (rDNA) están organizados en dos clases distintas, representadas por familias de genes altamente repetidas. Un a clase de rDNA, comprende los genes que codifican el RNA ribosómico 18S, 5.85 y 28S, la otra clase comprende los genes que codifican el RNA ribosómico 5S.
En el presente estudio, hemos localizado el 55 rDNA, en el cerdo dornéstico Sus scrofa, 2n=38) y sus relacionados salvajes el babirusa (Babyrousa babyrussa, 2n=38) y el pécari de hocico blanco (Tayassu pecan, 2n=26).
El cerdo y el babirusa pertenecen, los dos, a la familia Suidae, mientras que el pécari, se encuadra en una familia distinta: Dicotylidae.
Los cromosomas metafásicos fueron preparados a partir de linfocitos sanguíneos, siguiendo los procedimientos estándar, y los cromosomas fueron GTG-bandeados antes de la hibridación.
La hibridación fluorescente in situ fue llevada a cabo usando una sonda de ratón, que incluía el gen 121 bp5S rRNA. La numeración de los cromosomas del babirusa y el pécari se atiene a lo indicado por Bosma y de Haan (1981) y Hufty o tal. (1973) respectivamente.

Sujets

• Gene mapping
• Mapeo génico

Informations

• Publié par: erevistas
• Publié le: 01 janvier 1996
• Nombre de lectures: 14

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